TABLE OF CONTENTS Mass flowmeters measure mass directly, using the properties of mass, as opposed to those who measure volume or velocity. This type of meter is found in applications with changing fluid parameters. Meters that measure mass directly, in effect, weigh the fluid as it passes through the meter, yielding a highly accurate measurement that is virtually independent of varying process conditions. (See Figure 6-17.) The Coriolis principle flowmeter is a true mass flow flowmeter because it uses the properties of mass to measure mass.
Although true mass flowmeters are available, they are rarely applied due to their high costs. Therefore, two variables will be measured fluid velocity and fluid density. These two variables are to be multiplied and their product will be the mass flow.
M mass flow rate
A cross-sectional area of pipe interior density of fluid
P density of fluid
V velocity of fluid flow
Coriolis meters operate on the basic principle of motion mechanics. The fluid in motion through a vibrating flow tube is forced to take an acceleration as it moves toward the point of peak amplitude of vibration. Conversely, the fluid decelerates as it moves away from the point of peak amplitude as it exits the tube. The moving fluid exerts a force on the inlet side of the tube in resistance to this acceleration, causing this side of the tube to lag behind its non-flow position.
On the outlet side, the force-exerted by the flowing fluid is in...
